In the fish farming scenario, it will really depend on how the fish farms come to be. In what I described, there can be more farms, but in the model that's not problematic. There's just less fish to allocate: if a new farm appears, the contract would break down and a new one would be signed. The equilibrium of the model is for a contract to be signed, and for the lake to be fished efficiently.

The 1000 number was made up with no particular reference to the real number of fishermen in fisheries. Here there are some examples of real cases
http://www.perc.org/articles/community-run-fisheries-0 One of them has 99 fisherman (Port Lameron Harbor).

A counterexample to me is the largest lake fishery in the world: Lake Victoria's, with more than 100.000 fishermen. Here the fishery is controlled by a joint organisation made up by the governments that surround the Lake. And it doesn't seem to be able to stop overfishing. It's not a problem of government, here we have high monitoring costs, high communication costs, and argueably high time preference (fishermen in the area don't think in the very long term)
https://pseudoerasmus.com/2015/10/04/ce/

I am not opposed to all coercive cooperation. I prefer it to be voluntary, and show that the voluntary model can be extended far. But if it fails, then coercion is in these cases justified, as everyone involved benefits, and would hypothetically consent to it.

"I assume that the probability that you won’t be betrayed is 1. A realistic case is where P is sufficiently high. As far as I know, not even in the Soviet Union or North Korea is this prevalent. In those countries people usually honestly believe in their regime. They don’t rebel against the system because they endorse it. This makes the system stable. I don’t think a system can be made stable by fear alone, which is why I initially found Scott’s example a bit unnatural."

I disagree with basically everything here.

Re the Port Lameron Harbor fishery:

"Local fishers see themselves as having exclusive rights to their territory, which extends eleven miles along the coast and more than thirteen miles seaward. They actively defend it against outsiders."